Field of the Invention
The present invention relates to a roll over valve for a fuel tank of a vehicle, and more particularly, to a roll over valve for a fuel tank of a vehicle which can increase a fuel filling capacity of the fuel tank and improve venting performance by dividing a fuel inlet of the roll over valve for the fuel tank into two or more.
Description of Related Art
In general, under a situation in which a vehicle is inclined at a predetermined angle or more or turns over, a roll over valve is mounted inside the fuel tank, which prevents fuel from being leaked to a canister and evaporation gas in the fuel tank is collected in the canister through the roll over valve at ordinary time.
Herein, a single type roll over valve for the fuel tank in the related art will be described below.
FIGS. 1 and 2 are a perspective view and a schematic cross-sectional view illustrating a roll over valve for a fuel tank in the related art and FIG. 3 is a cross-sectional view illustrating a roll over valve operating state in the related art.
In FIGS. 1 and 2, reference numeral 10 represents a housing of the roll over valve.
A nipple 12 for connection with the canister is provided to discharge the evaporated gas is formed on the top of the housing 10, an inlet 14 into which the evaporated gas or the fuel is introduced is formed on the bottom of the housing 10, and a float 20 which is elevatable by buoyancy is embedded in the housing 10.
Further, an orifice 16 through which the evaporation gas is discharged is formed on the top of the housing 10, that is, just at an upper side corresponding to the top of the float 20 and a cut-off protrusion 22 that plugs up the orifice 16 integrally protrudes on the top of the float 20 in order to prevent the fuel from being discharged.
Therefore, when the fuel in the fuel tank is filled below the float 20, the evaporation gas evaporated from the fuel enters the inlet 14 of the housing 10 and passes through a gap between an inner wall of the housing 10 and the float 20 and thereafter, is discharged to the canister through the orifice 16 and the discharged evaporation gas is used for engine combustion as illustrated in FIG. 3A.
Further, when the fuel in the fuel tank 30 is filled above the float 20 and the buoyancy is applied to the float 20, the float 20 rises to allow a cut-off protrusion 22 of the float 20 to plug up the orifice 16, thereby preventing the fuel from being discharged to the outside through the canister.
In particular, as illustrated in FIG. 3B, even in the situation in which the vehicle is inclined at a predetermined angle or more or turns over, when the buoyancy is applied to the float 20 by the fuel in the fuel tank, the cut-off protrusion 22 of the float 20 plugs up the orifice 16, thereby preventing the fuel from being discharged to the outside through the canister.
In this case, a moment when the float 20 rises by the buoyancy to plug up the orifice 16 is called a clog point.
However, the roll over valve in the related art smoothly performs evaporation gas discharge and fuel cut-off functions, but a large upper space of the fuel tank remains as an available space in which the fuel can be filled when the fuel is cut off, and as a result, there is a problem in that an internal volume of the fuel tank is limited by the roll over valve's clog point.
By considering the problem, when the fuel tank having a large capacity is adopted, more fuel can be filled, but the size of fuel tank for the vehicle is limited in that the fuel tank for the vehicle adopts a fuel tank having a capacity in which more fuel can be filled in order to secure mounting spaces of adjacent components including an exhaust system component, a suspension, a spare tire, and the like.
Therefore, a dual type roll over valve may be mounted on the fuel tank in order to put more fuel in the fuel tank having the same size.
Referring to FIG. 4, in a dual type roll over valve, one roll over valve is mounted on each of both sides of the fuel tank and since the fuel is cut off in one of the two roll over valves while the vehicle is inclined at a predetermined angle or more, an upper space (the available space in which the fuel can be filled) of the fuel tank is smaller than the single type roll over valve when the fuel is cut off, thereby further increasing a fuel filling capacity for the fuel tank having the same volume.
However, in the dual type roll over valve, since two roll over valves are mounted on the fuel tank, the number of components increases and manufacturing cost increases.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.